Patent Literature 1 suggests a pressure sensor in which a pressure introduction hole is formed to pass through a case, and a sensor chip is arranged in the case to output a sensor signal according to a measurement medium.
Specifically, in such a pressure sensor, the pressure introduction hole is constructed by a first introduction hole extended in a predetermined direction and a second introduction hole extended in a direction perpendicular to the extending direction of the first introduction hole and communicated to the first introduction hole. That is, the pressure introduction hole has what is called L-shape. The sensor chip is arranged to close the first end opening of the first introduction hole opposite from the side where the first introduction hole is communicated to the second introduction hole.
Such a pressure sensor is attached and used for a component to be attached so that the second introduction hole of the pressure introduction hole is parallel to the vertical direction and that the other end opening of the pressure introduction hole opposite from the first end opening (opening of the second introduction hole opposite from the side where the second introduction hole is communicated to the first introduction hole) is located on the ground side. A sensor signal according to the measurement medium introduced into the pressure introduction hole is outputted from the sensor chip.
Accordingly, a water drop existing especially in the second introduction hole is drained by gravity, such that the pressure introduction hole is restricted from being closed.